Sökning: "Non-linear"

Visar resultat 6 - 10 av 1015 avhandlingar innehållade ordet Non-linear.

1. 6. A new non-linear GARCH model

   Författare :Gustaf E. Hagerud; Handelshögskolan i Stockholm; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : This dissertation contains four papers in the field of financial econometrics. In the first paper, A Smooth Transition ARCH Model for Asset Returns, a new class of ARCH models is introduced. The model class allows for non-linearity in the equation for the conditional variance. LÄS MER

3. 7. Theoretical perspectives on ultrafast and non-linear spectroscopy

   Författare :Emil Vinas Boström; Matematisk fysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Non-linear optics; Ultrafast dynamics; Non-equilibrium Green s functions; Density functional theory; Multi-photon absorption; Second harmonic generation; Desorption dynamics; Auger decay; Charge-separation dynamics; Quantum Zeno effect; Fysicumarkivet A:2018:Vinas Boström;

   Sammanfattning : In this thesis we discuss a theoretical description of ultrafast and non-linear spectroscopy. Due to the high intensities and ultrashort pulse durations involved in such experiments, it is necessary to use an explicitly time-dependent formalism. LÄS MER

4. 8. Quantum chemical calculations of non-linear optical absorption

   Författare :Peter Cronstrand; KTH; []
   Nyckelord :quantum chemical; non-linear optical; multi-photon absorption;

   Sammanfattning : This thesis represents a quantum chemical treatise ofvarious types of interactions between radiation and molecularsystems, with special emphasis on the nonlinear opticalprocesses of Multi-Photon Absorption and Excited StateAbsorption. Excitation energies, transition dipole moments,two-photon and three-photon tensor elements have beencalculated from different approaches; density functional theoryandab-initiotheory, employing different orders ofcorrelation treatment with the purpose to provide accuratevalues as well as evaluate the quality of the lower ordermethods. LÄS MER

5. 9. Variational Tensor-Based Models for Image Diffusion in Non-Linear Domains

   Författare :Freddie Åström; Michael Felsberg; George Baravdish; Reiner Lenz; Christoph Schnörr; Linköpings universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; image diffusion; variational formulation; denoising; tensor; non-linear;

   Sammanfattning : This dissertation addresses the problem of adaptive image filtering.Although the topic has a long history in the image processing community, researchers continuously present novel methods to obtain ever better image restoration results. LÄS MER

7. 10. Non-linear attosecond physics at 100 eV

   Författare :Alexander Muschet; Laszlo Veisz; Piotr Matyba; Per Eng-Johnsson; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; extreme ultraviolet XUV ; non-linear XUV – matter interaction; high-harmonic generation; photoionization; attosecond physics; isolated attosecond pulses; attosecond XUV pump – XUV probe spectroscopy; fysik; Physics;

   Sammanfattning : Non-linear interactions between light and matter have nowadays a broad range of applications. They are used for frequency doubling in simple laser pointers as well as for a variety of purposes in complex laser systems like the one presented in this thesis. LÄS MER